In the era of data-driven science, corpus-based language technology is an essential part of cyber physicalsystems. In this chapter, the authors describe the design and the development of an extensible domainspecificweb corpus to be used in a distributed social application for the care of the elderly at home.The domain of interest is the medical field of chronic diseases. The corpus is conceived as a flexible andextensible textual resource, where additional documents and additional languages will be appendedover time. The main purpose of the corpus is to be used for building and training language technologyapplications for the “layfication” of the specialized medical jargon. “Layfication” refers to the automaticidentification of more intuitive linguistic expressions that can help laypeople (e.g., patients, familycaregivers, and home care aides) understand medical terms, which often appear opaque. Exploratoryexperiments are presented and discussed.